Digital alarm clock

ABSTRACT

A digital alarm clock wherein an alarm mechanism is provided at the sides of the digital clock numerals. An elongated longitudinally moveable rod 76 extends from an electric motor 5 on one side of the digital alarm clock to an alarm cam mechanism 64-72 on the other side of the digital alarm clock for translating motion from one side to the other side of the clock.

United States Patent Marble Jan. 25, 1972 [54] DIGITAL ALARM CLOCK [72]Inventor: Chester B. Marble, Ashland, Mass.

[73] Assignee: General Electric Company [22] Filed: July 17, 1970 21Appl. No.: 55,817

52 US. Cl. ..58/22, 58/38, 58/125 c, 58/l6 [51] Int. Cl. ..G04b 23/02[58] FieldofSearch ..58/l6, l9,20,2l,2l.1,22, 58/30, 125 C [56]References Cited UN lTED STATES PATENTS 2,507,216 5/1950 Moss 2,768,33210/1956 Protzmannetal 3l7/99 Clark ..58/l6 2/l970 Funaki PrimaryExaminerRichard B. Wilkinson Assistant Examiner- Lawrence R. FranklinAtlorneyLawrence R. Kempton, Leonard J. Platt, John F. Cullen, Frank L.Neuhauser, Oscar B. Waddell and Joseph B. Forman 5 7 ABSTRACT A digitalalarm clock wherein an alarm mechanism is provided at the sides of thedigital clock numerals. An elongated longitudinally moveable rod 76extends from an electric motor 5 on one side of the digital alarm clockto an alarm cam mechanism 64-72 on the other side of the digital alarmclock for translating motion from one side to the other side of theclock.

10 Claims, 6 Drawing Figures PATENIEU JANZS m2 SHEET 1 OF 2 3 rwf w w H%u W5 I k w 5 9 w b DIGITAL ALARM CLOCK BACKGROUND OF THE INVENTION Thisinvention relates to a digital alarm clock and, more particularly, to aunique alarm control mechanism for a digital clock.

In the construction of digital clocks, it is conventional to locate thetime-indicating numerals of the digital clock on drums or pages whichare centrally positioned between two side-supporting plates. It is alsocommon practice to provide an electric motor and audible alarm vibratoron one side of the numerals, and an alarm time indicator and cammechanism on the other side of the clock numerals. A low-cost alarmmovement which may be conveniently incorporated into such a digitalalarm clock and which has a readily movable linkage extending from theelectric motor side to the alarm time-indicating side of such a digitalalarm clock is especially desirable.

In a prior US. Pat. No. 2,768,332 to Protzmann et al., dated Oct. 23,1956, and assigned to the same assignee as the present invention, thereis disclosed an alarm mechanism including a bellcrank lever 13 which isarranged to be resiliently urged toward an alarm cam gear 3 by aresilient vibrator arm 10. With such an alarm control mechanism amanually movable shutoff lever 11 may be provided for lifting theresilient vibrator arm to remove the spring force from the bellcrank l3and the axially movable cam gear 3 when the alarm has been shut off.This construction prevents the occurrence of an undesirable clickingnoise which would occur when the cam gear 3 passes through the positionin which the alarm-actuating movement would normally occur.'

This invention is concerned with such a digital alarm clock movement andhas its general object the provision of a lowcost digital alarm clock inwhich the parts are constructed so that an objectionable click is notheard on the days when it is not desired to have the alarm sound.

It is also an object of this invention to provide an improved digitalalarm mechanism having a minimum number of parts which may be readilyincorporated in a digital clock.

SUMMARY OF THE INVENTION In accordance with one of the aspects of thisinvention, two generally parallel sideplates are provided for supportingdigital numerals between the plates. An electric motor is mounted on theoutside of one of the plates and an alarm time control cam is mounted onthe outside of the other plate. A resilient vibrator is mounted adjacentto the motor and is arranged to provide the resilient force necessary tomove a continuously rotated alarm cam toward the alarm time control cam.To achieve this in a unique and low-cost manner, an elongatedlongitudinally slidable rod is loosely positioned within an aperture inone of the plates for cooperating with the vibrator on the motor side ofthe alarm clock and the continuously rotated gear on the other side ofthe alarm clock. By this arrangement, at a preset alarm time theresilient vibrator arm slides the elongated rod to move the continuouslyrotated alarm cam toward the alarm time control cam to thereby releasethe alarm vibrator to sound the alarm.

With this construction,- a minimum number of parts are required fortransmitting motion from the alarm vibrator on one side of the clock tothe alarm cams on the other side of the clock. A simple loosely mountedelongated rod is all that is required to translate motion from one sideto the other side. Moreover, the parts are arranged so that motion istranslated in the appropriate direction with a minimum number of parts.

It can also be appreciated that a "no click alarm clock is also achievedsince a manual alarm shutoff lever may be provided for lifting theresilient vibrator to shut off the alarm. With this construction, whenthe vibrator is lifted the longitudinally slidable rod does not exert aforce on the continuously rotated cam which could cause an objectableclick at the alarm set time.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and attendant advantagesof this invention will be apparent from the following description takenin connection with the accompanying drawings in which:

FIG. 1 is a front perspective view of a digital alarm clock constructedin accordance with my invention;

FIG. 2 is a rear perspective view of the alarm clock shown in FIG. I;

FIG. 3 is a partial exploded perspective view of a portion of the alarmcontrol mechanism of the alarm clock shown in FIG.

FIG. 4 is a partial rear elevational view of the alarm clock shown inFIG. 1 with the parts in the alarm-sounding position;

FIG. 5 is a fragmentary rear elevational view similar to FIG. 4 with theparts held in the alarm set position by the alarm control mechanism; and

FIG. 6 is a fragmentary front perspective view of the casing and thealarm time-indicating drum of the digital alarm clock shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsand first particularly to FIG.

I, there is shown a digital alarm clock which includes my uniquelow-cost alarm control mechanism. As shown, the digital clock numeralsmay conventionally include two sets of pages 2 and 4 which. arecentrally positioned on the clock for indicating the time of day.

The digital alarm clock may be driven by conventional timing mechanismincluding a self-starting synchronous motor 5. Portions of the motorstator magnetic core and energizing coil are shown at 6 and 8,respectively. A resilient magnetic vibrator l0 operated by leakage fluxfrom the motor is arranged to have its free end portion 12 vibrateagainst a stator portion 14 and produce an audible alami at all timeswhen the motor is energized unless the vibrator is prevented fromvibrating hy a manual alarm shutoff lever 16, or my unique automaticalarm control mechanism including a bellcrank lever 18.

As shown more particularly in FIG. 2, the manual alarm shutoff lever 16may be suitably mounted on a supporting plate 17 of the clock motor andhas a projection 20 thereon which is positioned so as to engage the freeend 12 of the vibrator arm 10. A knob 22 which may extend outside of theclock casing is fixed to the lever 16 for sliding the lever to the leftto shut off the alarm, or to the right to the position shown in FIG. 2to allow the alarm to sound at the preset time.

The bellcrank lever 18 for automatically permitting the alarm to soundat a preset time is generally similar to the bellcrank lever 13 as shownin FIG. 2 of the aforementioned US. Pat. No. 2,768,332 issued Oct. 23,1956 to D. E. Protzmann et al. As illustrated in FIGS. 2 and 5 of theinstant application, the bellcrank lever I8 is pivoted to themotor-supporting plate 17 by means of ears 28 and a pivot pin 30, andthe resilient vibrator arm I0 is utilized to-spring load the bellcranklever. It can be seen that when the shutoff lever 16 is moved to theleft, the projecting portion 20 is brought into engagement with the end12 of vibrator arm 10 forcing it out of engagement with the bellcrank 18thereby not only restraining vibratory movement of the vibrator arm, butalso removing the spring force of the vibrator from bellcrank lever 18.

A supporting structure including two sideplates 32 and 34 is providedfor supporting the two sets of pages 2 and 4 for indicating the time ofday. As shown more particularly in FIG. 1, I

the sideplates 32 and 34 are arranged generally parallel to each other,and a plurality of spacer posts 36, 38 and 40 are provided for securelyconnecting the plates to each other in the desired spaced relationship.

As shown in FIG. I, the synchronous motor 5 for driving the pages of theclock is suitably connected to sideplate 32 of the page-supportingstructure. To achieve this with a minimum number of parts, suitablespacer posts 42 and 44 are provided for connecting the motor-mountingplate 17 in spaced parallel relationship with respect to sideplate 32.

With this arrangement, reduction gearing 46 from the clock motor may bepositioned between the motor-supporting plate 17 and the sideplate 32for driving the sets of pages 2 and 4 of the digital clock at theappropriate synchronous speed. The digital numerals may be adjusted andset by means of an adjusting wheel 48 which is also suitably mountedbetween the sideplate 32 and the motor-mounting plate 17. In aconventional manner not shown, the adjusting wheel 48 is arranged inmesh with the reduction gearing 46 of the clock motor for setting thetime-indicating pages of the digital clock.

The reduction gearing 46 between the motor-mounting plate 17 andslideplate 32 drives a center shaft 50 of the digital clock movement atl revolution per hour. As shown more particularly in FIGS. 3, 4 and 5,the center shaft 50 extends from the motor side of the digital clock tothe alarm control mechanism side of the digital clock and is supportedin suitable bearings which are provided in the sideplates 32 and 34.

ALARM CONTROL MECHANISM According to this invention, there is combinedwith the aforedescribed digital clock elements a uniquely designed andpositioned alarm control mechanism which may utilize the alarm vibratorat the left side of the clock for sounding an audible alarm at theappropriate time. The mechanism utilizes the output from the centershaft 50 for driving a 12-hour cam mechanism which cooperates with amanually adjustable alarm set cam for causing the alarm vibrator 10 tosound at the preset time.

As shown more particularly in FIGS. 2 and 3, a gear 56 may be fixed tothe central power output shaft 50 for rotation along with the shaft 50at I revolution per hour. Suitable reduction gearing 58 and 60 ismounted on a stub shaft 62 fixed to plate 34 for rotating a cam gear 64at I revolution every [2 hours. As illustrated more particularly in FIG.3, the cam gear 64 is suitably mounted on a centrally located bearingshaft 50 of the digital clock-supporting structure, and has twoprojecting cam portions 66 integrally formed thereon. The cam portions66 comprise abrupt axially extending cam surfaces 68 located on one sidethereof and sloped cam surfaces 70 located on the other. Thecontinuously rotated axially movable cam 64 is arranged for cooperationwith a manually adjustable alarm time cam 72. As shown in FIG. 3, thealarm time cam is provided with abrupt cam surfaces formed by two slots74 for cooperating with the abrupt cam surfaces 68 of the axiallymovable continuously rotated alarm time cam 64.

My unique reliable and low-cost mechanism for utilizing the vibrator arm10 on the electric motor side of the digital alarm clock for providingthe resilient force necessary to urge the continuously rotated l2-hourcam 64 toward the manually settable alarm time cam 72 will now be moreparticularly described. The mechanism includes two principal parts. Areadily movable longitudinally slidable rod 76 which extends from theelectric motor side to the alarm cam side of the digital alarm clock,and a readily formed alarm actuator lever 78 which is arranged betweenthe continuously rotated I2- hour cam gear 64 and the longitudinallyslidable rod 76. As shown more particularly in FIGS. 1 and 3, the alarmactuator lever 78 may be formed from flat sheet metal and it extendsfrom its pivot 80 at the front right corner of the digital alarm clockupwardly and rearwardly to the upper right rear corner of the digitalalarm clock where it cooperates with the elongated longitudinallyslidable rod 76. In accordance with my invention, the pivot 80 for thealarm actuator lever 78 may be formed from an extension of the spacerpost 36. With this arrangement, the pivot 80 is provided without the useof additional materials.

A similar low-cost reliable arrangement is also provided for guiding theupper portion of the alarm-actuating lever 78. As illustrated, anaperture 83 is formed in the lever 78 for cooperating with guidepost 84which may be readily staked to sideplate 34. A suitable enlargedaperture 86 may be formed in the alarm actuator lever 78 for receivingpinion gear 60 of the reduction gearing for the continuously rotated camgear 64, and another enlarged aperture 88 is also formed in the alarmactuator lever for receiving the end portion of shaft 50.

The elongated rod 76 which extends from one side of the digital alarmclock to the other side of the alarm clock may be readily and reliablymounted without the use of any additional parts. As shown moreparticularly in FIG. 2, an aperture 90 is formed in sideplate 34 forreceiving one end of the elongated rod 76 while another aperture 92 isformed in the motor-supporting plate 17 for guiding the other end of theelongated rod.

With this unique arrangement, it can be appreciated that the resilientvibrator alarm 10 provides the force required for urging thecontinuously rotated alarm cam gear 64 into engagement with the manuallyset alarm time gear 72. With particular reference to FIGS. 3 and 5, itcan be seen that the end 12 of the vibrator is urged downwardly againstthe upper portion of bellcrank lever 18, thereby causing the bellcranklever to pivot to the left as shown in FIGS. 3 and 5 to urge theelongated rod 76 to the left to thereby urge the actuator lever 78 tothe left about its pivot 80, and the continuously rotated cam gear 64 tothe left into engagement with the manually settable alarm time gear 72.

As shown more particularly in FIGS. 3, 4 and 5, suitable protrusions 94and 96 may be readily formed on the outside surface of alarm-actuatinglever 78 for providing low-friction contact between the alarm-actuatinglever 78 and the side surface of the continuously rotated cam 64. Asshown more particularly in FIGS. 3 and 5, a screw 98 may be threadedinto the upper portion of lever 78 for providing a contact surface withthe end of elongated rod 76. Naturally, the screw also provides anarrangement to compensate for manufacturing tolerances between thebellcrank lever 18, vibrator l0, alarm actuator lever 78, and thecontinuously rotated cam 64.

A unique low-cost arrangement is also provided for indicating the alarmtime cam setting of the manually adjustable cam 72. As shown moreparticularly in FIG. 3, the alarm time cam 72 includes a shaft portion100, an inside surface 102 which is provided with the slots 74 forcooperating with the cam projections 66 on the continuously rotated camgear 64, and a surface 104 for cooperating with an alarm time-indicatingdrum 106. In order to mount the alarm time-indicating drum 106 on thealarm time cam 72, it is merely necessary to place an aperture 108formed in the drum over a cylindrical guide surface 10 of the alarm timecam 72, and then place a flat metal spring washer 110 over the end ofdrum 106. Suitable projections lll extend outwardly from the alarm timecam 72 for connecting the washer I10 to the alarm time cam 72. Thus, thealarm time-indicating drum 106 is frictionally held between the alarmtime cam 72 and the flexible metal washer 110. By this construction, thealarm time-indicating drum 106 may be rotated relative to the alarm timecam in order to set the numerals on the drum to the appropriate relativeposition with respect to the cams 66 and 74 during manufacture of theclock. The friction washer 110 provides sufficient force against theside surface of the alarm time-indicating drum 106 so that the drum 106is carried with the cam 72 as the cam is rotated to change the alarmtime setting of the digital alarm clock.

In order to set the alarm time from outside of the clock casing, asuitable gearwheel 112 is mounted on a stub shaft 113 which is staked tothe sideplate 34. As shown more particularly in FIG. 2, gear 112 isarranged to be in mesh with gear teeth 1 I5 formed on the outerperiphery of the alarm time set gear 72, and thus manual adjustingmovement of gear 112 causes corresponding movement of the alarm time camgear 72 and the alarm time-indicating drum 106.

A readily formed indexing mechanism is provided for bolding the alarmtime-indicating drum I06 and the alarm time cam 72 in any one of aplurality of alarm time set positions. As shown more particularly inFIG. I, a detent lever is provided with a bored sleeve 122 and ismounted on a post 124 which may be staked to the outside of sideplate34. A suitable spring I26 is positioned between the sideplate 34 and theindexing lever 120 for resiliently urging the detent lever 120 towardthe gear teeth 115 which are formed on the outer periphery of the alarmtime set cam 72. The spring 126 is of sufficient force so that a detent130 at the end of the detent lever 120 will be urged into engagementwith the teeth 115 with such force as to permit alarm set cam gear 72 tobe adjusted and readily moved by simply rotating the adjusting wheel 112which protrudes from the bottom of the clock casing, and yet, the springis of sufficient force to hold the alarm set cam 72 in its adjustedposition after it has been set.

OPERATION If, for example, it is desired to have the alarm ring at 7oclock in the morning, the operator rotates adjusting wheel 112 to setthe alarm cam 72 and the alarm set-indicating drum 106 to theappropriate 7 a.m. position, as indicated in FIG. 6. Then the operatorslides the alarm shutoff lever 16 to the right as shown in FIG. 2 toremove the end of vibrator 10 from the projection on the alarm shutofflever 16. This allows the projection 12 on the end of the vibrator to beplaced in engagement with the bellcrank lever 18. Accordingly, thespring force of the vibrator 10 is placed on the bellcrank lever 18, theelongated shaft 76, the alarm-actuating lever 78, and the right sidesurface of the continuously rotated cam gear 64, as shown in FIGS. 3, 4and 5. Thus, the cam surfaces 70 of the continuously rotated cam gearwill ride on the inside surface of the time set cam 72 as thecontinuously rotated gear 64 is rotated by the synchronous motor of theclock.

At 7 oclock in the morning, the abrupt cam surfaces 68 become alignedwith the abrupt cam surfaces 75 formed by slots 74 in the alarm set cam72, and the vibrator arm 10 acting through the bellcrank lever 18, theelongated rod 76, and the alarm actuator lever 78 rapidly forces thecontinuously rotated cam gear 64 toward the time set cam gear 72 fromthe position shown in FIG. 5 to the position shown in FIG. 4. In theFIG. 4 position, the vibrator arm 10 is unrestrained and is free tovibrate under the influence of the continuously applied electromagneticforces to give an audible alarm signal.

When the alarm has sounded, the operator simply grasps knob 22 to slidethe alarm shutoff lever 16 to the left from the position shown in FIG. 2to thereby move the projection 20 on the shutoff lever into engagementwith the end 12 of the vibrator arm forcing it out of engagement withthe bellcrank lever 18 and restraining further vibratory movement of thevibrator arm. It can be appreciated that when the vibrator shutoff leverholds the vibrator in this position, the spring force of the vibrator isremoved from the bellcrank lever 18, the elongated rod 76, the flatalarm actuator lever 78, and the continuously rotated cam gear 64. Thus,should the alarm shutofi' lever 16 remain in this position for another12 hours at which time the abrupt cam surfaces 68 on the continuouslyrotated gear 64 are placed in alignment with the slots 74 on the alarmtime set cam, the cam surfaces 68 will not be rapidly forced intoengagement with the alarm set cam 72 to thereby create an objectionableclick since the continuously rotated alarm cam 64 is not being urged tothe left, as viewed in FIG. 3, under the force of the resilient vibratorarm 10.

From the foregoing description, it will be appreciated that my uniquealarm control mechanism is achieved with the use of a minimum number ofparts'which are reliably arranged with respect to each other. Theelongated rod 76 which is utilized for translating motion from theelectric motor side of the digital clock to the alarm cam side of theclock is a simple cylindrical rod which is arranged for longitudinalslidable motion in apertures 90 and 92 which may be readily formed inplate 34 and the motor-mounting plate 17, respectively, at the same timethat these plates are being punched to provide other apertures and tabs.Moreover, with this unique arrangement of parts, it is not necessary toconnect any levers or other mechanisms to the elongated rod 76 since thetranslating motion of the rod is simple longitudinal sliding motionrather than rotary motion which is required in some prior artmotiontranslating arrangements. In like manner, the alarm-actuatinglever 78 which is positioned at one end of the longitudinally slidablerod may be stamped from a single piece of metal, and may be pivotallymounted on an existing spacer post 80 of the digital clock. Thus, anexceedingly simple, yet reliable digital clock alarm mechanism has beenachieved.

What I claim is:

l. A digital alarm clock comprising:

a. a supporting structure;

b. digital clock numerals generally centrally positioned on saidsupporting structure;

c. an electric motor for driving said digital clock numerals fixed toone side of said supporting structure;

(I. an alarm mechanism having a resilient vibrator arm for causing anaudible sound upon vibration thereof connected to said electric motor onsaid one side of said supporting structure;

e. a first cam gear rotatably mounted on the other side of saidsupporting structure and continuously rotated as a function of time bysaid electric motor;

. a rotatably mounted alarm time control cam member positioned adjacentto said first cam member for permitting movement of first said cammember at a preset alarm time;

g. an elongated axially movable rod mounted on said supporting structureand extending from one side of said supporting structure to the otherside of said supporting structure, one end of said rod being arrangedfor longitudinal slidable movement by the resilient vibrator arm; and

h. means in engagement with the other end of said rod and said first camgear for permitting said resilient vibrator arm to longitudinally slidesaid rod and said first cam gear toward the alarm time control cam tothereby release the alarm vibrator arm to sound the alarm at a presetalarm time.

2. A digital alarm clock as defined in claim 1 wherein a generally flatlever is pivotally mounted on said supporting structure and ispositioned between the other end of said elongated rod and said firstcam gear for permitting said resilient vibrator arm to longitudinallyslide said rod and said first cam gear toward the alarm time control camto thereby release the alarm vibrator arm to sound the alarm at a presettime.

3. A digital alarm clock as defined in claim 1 wherein an alarmtime-indicating drum is mounted on the alarm time control cam, and aspring member is fixed to the alarm time control cam for resilientlyurging said indicating drum into frictional engagement with said alarmtime control cam.

4. A digital alarm clock as defined in claim 3 wherein gear teeth areformed on the outer periphery of said alarm time control cam and agearwheel is positioned in mesh with the teeth on the alarm time controlcam for adjusting the relative position of the alarm time control camwith respect to the continuously rotated gear.

5. A digital alarm clock as defined in claim 4 wherein an indexing leveris pivotally mounted on said supporting structure and is spring urgedagainst the teeth formed on the periphery of the alarm time control camfor holding the alarm time control cam and the alarm time-indicatingdrum in any one of a plurality of alarm time set positions.

6. A digital alarm clock comprising:

a. a supporting structure including two sideplates arranged generallyparallel to each other and held spaced from each other by a plurality ofspacer posts;

b. digital clock numerals positioned between said sideplates;

c. an electric motor for driving said digital clock numerals fixed toone of said sideplates;

d. an alarm mechanism having a resilient vibrator arm for causing anaudible sound upon vibration thereof connected to said electric motor;

e. a pivotally mounted bellcrank lever having a first portion forengaging said vibrator to restrain vibratory movement thereof;

f. a first cam gear rotatably mounted adjacent to said outer plate andcontinuously rotated as a function of time by said electric motor;

y g. a rotatably mounted alarm time cam member positioned adjacent tosaid first cam gear for permitting axial movement of said first cam gearat a preset alarm time;

h. a generally flat lever mounted adjacent to said axially movable camgear for movement thereby;

. an elongated slidable rod extending through an aperture in one of saidsideplates, one end of said elongated slidable rod being arranged forengagement with a second portion of said bellcrank lever, and the otherend of said elongated rod being in engagement with said flat lever, saidvibrator arm exerting a spring force on said bellcrank lever for causingpivotal rotation thereof and longitudinal slidable motion of saidelongated rod toward said flat lever; and

. said first cam gear and said alarm time cam cooperating to cause axialmovement of said first cam gear upon relative rotation of said cams as afunction of time through a predetermined relative angular movement ofsaid cam members for allowing said elongated rod to slide toward saidfirst cam gear to thereby allow said bellcrank lever to pivot to releasethe alarm vibrator to sound the alarm. 7. A digital alarm clock asdefined in claim 6 wherein said flat lever is pivotally mounted on oneof said spacer posts and is provided with an aperture for receiving aguidepost which is fixed to one of said sideplates in order to pivotallymount and guide said lever on said clock-supporting structure.

8. A digital alarm clock as defined in claim 6 wherein a screw isthreaded into an upper portion of said generally flat lever forproviding a contact surface with the end of the elongated rod and forcompensating for manufacturing tolerances between the bellcrank lever,the alarm vibrator, the flat alarm actuator lever and the first camgear.

9. A digital alarm clock as defined in claim 6 wherein the electricmotor is supported on a supporting plate which is arranged generallyparallel to and spaced from one of said sideplates.

10. A digital alarm clock as defined in claim 9 wherein an aperture isprovided in one of said sideplates for guiding one end of said elongatedrod and an aperture is provided in the motor-supporting plate forguiding the other end of the elongated rod.

1. A digital alarm clock comprising: a. a supporting structure; b.digital clock numerals generally centrally positioned on said supportingstructure; c. an electric motor for driving said digital clock numeralsfixed to one side of said supporting structure; d. an alarm mechanismhaving a resilient vibrator arm for causing an audible sound uponvibration thereof connected to said electric motor on said one side ofsaid supporting structure; e. a first cam gear rotatably mounted on theother side of said supporting structure and continuously rotated as afunction of time by said electric motor; f. a rotatably mounted alarmtime control cam member positioned adjacent to said first cam member forpermitting movement of first said cam member at a preset alarm time; g.an elongated axially movable rod mounted on said supporting structureand extending from one side of said supporting structure to the otherside of said supporting structure, one end of said rod being arrangedfor longitudinal slidable movement by the resilient vibrator arm; and h.means in engagement with the other end of said rod and said first camgear for permitting said resilient vibrator arm to longitudinally slidesaid rod and said first cam gear toward the alarm time control cam tothereby release the alarm vibrator arm to sound the alarm at a presetalarm time.
 2. A digital alarm clock as defined in claim 1 wherein agenerally flat lever is pivotally mounted on said supporting structureand is positioned between the other end of said elongated rod and saidfirst cam gear for permitting said resilient vibrator arm tolongitudinally slide said rod and said first cam gear toward the alarmtime control cam to thereby release the alarm vibratOr arm to sound thealarm at a preset time.
 3. A digital alarm clock as defined in claim 1wherein an alarm time-indicating drum is mounted on the alarm timecontrol cam, and a spring member is fixed to the alarm time control camfor resiliently urging said indicating drum into frictional engagementwith said alarm time control cam.
 4. A digital alarm clock as defined inclaim 3 wherein gear teeth are formed on the outer periphery of saidalarm time control cam and a gearwheel is positioned in mesh with theteeth on the alarm time control cam for adjusting the relative positionof the alarm time control cam with respect to the continuously rotatedgear.
 5. A digital alarm clock as defined in claim 4 wherein an indexinglever is pivotally mounted on said supporting structure and is springurged against the teeth formed on the periphery of the alarm timecontrol cam for holding the alarm time control cam and the alarmtime-indicating drum in any one of a plurality of alarm time setpositions.
 6. A digital alarm clock comprising: a. a supportingstructure including two sideplates arranged generally parallel to eachother and held spaced from each other by a plurality of spacer posts; b.digital clock numerals positioned between said sideplates; c. anelectric motor for driving said digital clock numerals fixed to one ofsaid sideplates; d. an alarm mechanism having a resilient vibrator armfor causing an audible sound upon vibration thereof connected to saidelectric motor; e. a pivotally mounted bellcrank lever having a firstportion for engaging said vibrator to restrain vibratory movementthereof; f. a first cam gear rotatably mounted adjacent to said otherplate and continuously rotated as a function of time by said electricmotor; g. a rotatably mounted alarm time cam member positioned adjacentto said first cam gear for permitting axial movement of said first camgear at a preset alarm time; h. a generally flat lever mounted adjacentto said axially movable cam gear for movement thereby; i. an elongatedslidable rod extending through an aperture in one of said sideplates,one end of said elongated slidable rod being arranged for engagementwith a second portion of said bellcrank lever, and the other end of saidelongated rod being in engagement with said flat lever, said vibratorarm exerting a spring force on said bellcrank lever for causing pivotalrotation thereof and longitudinal slidable motion of said elongated rodtoward said flat lever; and j. said first cam gear and said alarm timecam cooperating to cause axial movement of said first cam gear uponrelative rotation of said cams as a function of time through apredetermined relative angular movement of said cam members for allowingsaid elongated rod to slide toward said first cam gear to thereby allowsaid bellcrank lever to pivot to release the alarm vibrator to sound thealarm.
 7. A digital alarm clock as defined in claim 6 wherein said flatlever is pivotally mounted on one of said spacer posts and is providedwith an aperture for receiving a guidepost which is fixed to one of saidsideplates in order to pivotally mount and guide said lever on saidclock-supporting structure.
 8. A digital alarm clock as defined in claim6 wherein a screw is threaded into an upper portion of said generallyflat lever for providing a contact surface with the end of the elongatedrod and for compensating for manufacturing tolerances between thebellcrank lever, the alarm vibrator, the flat alarm actuator lever andthe first cam gear.
 9. A digital alarm clock as defined in claim 6wherein the electric motor is supported on a supporting plate which isarranged generally parallel to and spaced from one of said sideplates.10. A digital alarm clock as defined in claim 9 wherein an aperture isprovided in one of said sideplates for guiding one end of said elongatedrod and an aperture is provided in the motor-supporting plate forguiding the other end of the elOngated rod.